GB1296923A - - Google Patents

Abstract

1296923 Super-conductors COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT 20 Feb 1970 8389/70 Addition to 1277797 Headings H1A A5 and A4D A hollow super-conductor cable is produced by assembling a plurality of the stabilized composite super-conductors of the parent Specification so as to create one or more longitudinal coolant channels. In a first embodiment, Figs. 1 and 2 (not shown).a plurality of blocks (2) comprising stabilized multi-strand super-conductors are placed between two plates (1) of normal metal leaving longitudinally extending spaces (4). The components are then bonded together by hot-rolling in such a way that the spaces (4) are not closed. Strengthening wires may be incorporated between the super-conductor elements. In second embodiment, Fig. 3 (not shown), a pair of strips containing groups of super-conductor elements are joined together by strips of normal metal placed between them along their edges and welded using a laser, a microplasma, diffusion or electron bombardment under vacuum or gas or using tungsten electrodes under inert gas. In a modification, Fig. 4 (not shown), the edge strips are formed integrally with one conductor strip. In a third embodiment, Fig. 5 (not shown), composite members are bent to form rectangular tubes and are welded together to form a strip with a plurality of coolant ducts. In a further embodiment, Figs. 6 and 7 (not shown), two composite members are placed together with interposed strips of a masking material, e.g. ink. The strips are then hot-rolled so that they are joined only at the gaps between the masking strips. The assembly is then inflated by internal fluid-pressure to separate the masked parts of the strips to form coolant channels. In a modification, Fig. 8 (not shown), the masking is omitted, the two members are welded together along their edges and the assembly is inflated to form a hollow conductor. The internal walls of the channels may be provided with grooves Fig. 10 (not shown), or with a porous inner surface layer, Fig. 11 (not shown), to aid cooling. The size of any of the arrangements may be reduced by cold drawing or wire drawing with or without a mandrel. The super-conductor elements may be of NbTi NbZr, NbTiZr, NbNiTa wires or of strips of Nb 3 Sn or Nb 3 AlGe. the ,stabilizing material may be Cu, Al or Ag and the channels may have square, round, rectangular or hexagonal cross-sections.